Drug & supplement interaction

Terminalia + Selpercatinib

Selpercatinib brand name: Retevmo.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Terminalia has a moderate interaction with Selpercatinib. Theoretically, use of Terminalia arjuna may increase the levels and clinical effects of CYP3A4 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Terminalia and Selpercatinib

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Selpercatinib

Selpercatinib falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Terminalia interacts with.

Theoretically, use of Terminalia arjuna may increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that Terminalia arjuna extract inhibits CYP3A4 enzymes and reduces CYP3A4 substrate metabolism.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the connection worth knowing about. Your body relies on a liver enzyme called CYP3A4 to break down selpercatinib (Retevmo) and keep its levels steady. Lab studies suggest Terminalia arjuna may slow that same enzyme down. If that happens in real life, selpercatinib could build up higher than intended, which may mean more of its known side effects, things like high blood pressure, liver enzyme changes, swelling, dry mouth, diarrhea, or heart rhythm shifts (QT prolongation).

I want to be honest about the strength here: this is based on test-tube research only, not human studies, so it's more of a theoretical caution than a proven problem. Still, with a serious cancer medicine like this, I wouldn't combine them on your own. Please run it past your oncology team or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Varghese A, Savai J, Pandita N, Gaud RS. In vitro modulatory effects of Terminalia arjuna, arjunic acid, arjunetin, and arjungenin on CYP3A4, CYP2D6, and CYP2C9 enzyme activity in human liver microsomes. Toxicology Reports. 2015(2):806-16. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Terminalia Also Interacts With Other Medications

Terminalia has 932 moderate known drug interactions in our database — the Selpercatinib one above is one of them. If you take anything else, check it against the full list below.

Moderate 932 No known interaction 1,898 (incl. Selpercatinib)
Taking anything else?

Check Another of Your Medications Against Terminalia

Covers the 2,830 medications we’ve checked against Terminalia. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Selpercatinib

This page covers Terminalia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Selpercatinib page lists 178 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 132 moderate · 35 minor.

From our pharmacist’s overview on the Selpercatinib page

“People facing a RET-driven lung or thyroid cancer often add supplements for strength, sleep, or immune support, and with selpercatinib (Retevmo) that instinct needs a careful check. Eleven of the 178 ingredients here carry a major rating, and the largest cluster affects how the drug is cleared by the CYP3A4 enzyme: St.”

Reviewed by 2 · Jul 18, 2026

Open the Selpercatinib interaction page

One more smart check

Taking Terminalia as Part of a Dietary Supplement Product? Check It for Interactions

We hold 306 real supplement products containing Terminalia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Terminalia. Your product may carry other ingredients that interact with Selpercatinib too, on top of Terminalia — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Terminalia and Selpercatinib Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Terminalia
Top 25%

#313 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Selpercatinib
Steady interest

#1,667 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Terminalia

What is Terminalia?

Terminalia
  • Heart health and circulation
  • Digestive problems (constipation, diarrhea)
  • Cholesterol support
  • Antioxidant and anti-inflammatory support
  • Immune support

Terminalia is a group of traditional Ayurvedic tree species (most notably Terminalia arjuna) used for heart, digestive, and general wellness purposes. Some small studies suggest possible benefits for heart and cholesterol health, but the evidence is limited and not strong enough to recommend it as a treatment. Talk to your pharmacist or doctor before using it, especially if you have a heart condition.

Read the full Terminalia monograph & all interactions
Medication

About Selpercatinib

What Is Selpercatinib Used For?

Brand name: Retevmo

Selpercatinib treats cancers driven by changes in the RET gene — either a gene fusion (where RET joins abnormally with another gene) or a RET mutation (a change in the gene itself). Your doctor will confirm one of these changes with an FDA-approved test before prescribing it.

It is approved for adults with RET fusion-positive non-small cell lung cancer; adults and children 2 and older with RET-mutant medullary thyroid cancer or RET fusion-positive thyroid cancer; and adults and children 2 and older with other advanced solid tumors that have a RET gene fusion and have not responded to prior treatment.

See full Selpercatinib drug information
Keep checking

Other Drugs & Terminalia

Browse every other medication we’ve checked against Terminalia — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
932Moderate
0Minor
1,897No known interaction
932 Moderate 1,897 No interaction
Moderate

932 interactions

Showing 60 of 932 moderate interactions — see all 932 on the Terminalia page.

No interaction 1,897 drugs checked — show the list

We also checked Terminalia against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,897 medications checked with no known interaction — see the full Terminalia list.

See the full Terminalia interactions page
See every supplement checked against Selpercatinib, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Terminalia monograph › Uses, safety, and every drug interaction in one place Selpercatinib supplement interactions › Every supplement checked against Selpercatinib, ranked by severity Selpercatinib drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Terminalia and Selpercatinib Together: Common Questions

Can you take Terminalia with Selpercatinib?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Terminalia and Selpercatinib interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Selpercatinib and Terminalia?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.